It’s been almost 20 years since the world lost Princess Diana in a tragic car accident. Her eldest son, Prince William, opened up about missing his mother and how her death took a toll on his mental health. According to People, the Duke of Cambridge talked to British GQ for the publication’s July cover story and said that he’s devastated about the fact that his mother will never know his family.

William said it’s taken him almost the full 20 years to recover from his mother’s death. It was incredibly public and “raw” at the time, and there was no chance for William and Harry to mourn privately. William told British GQ,

Because of his personal struggles with mental health, his work — along with brother Harry and wife Kate’s — with the Heads Together campaign is incredibly important to him.

He said that clear and honest communication is the key to unlocking the stigma. We must address mental health bluntly and help people be less afraid of their feelings.

We’re so glad William and his family are drawing attention to this important cause, and that the Duke of Cambridge seems to be in such a healthy place right now.